Osp is a clustered village on the outskirts of the Osapska dolina (Osp Valley) with the hamlets of Pod Steno, Katinara and Mlinarji where a mill once stood along the Osp River.

The Osp Valley and the steep Karst slope (called Stena or Griža), which surrounds the village, form the characteristic passable landscape – Bržanija that begins in Dolina in the hinterland of Trieste in the northwest and stretches from Socerb to Črni Kal, Bezovica and Podpeč. One of the area’s natural features is the Osp Cave or Grad in a steep Karst slope with the visible remains of a medieval fort. The cave is also an important archaeological site with numerous prehistoric, antique and early medieval finds. During the Ottoman invasions and the Austro-Venetian wars, the overhanging rock provided security and protection to the locals.The first records of archaeological finds in Osp date back to the early 1880s, when the attention of archaeologists and antique lovers was captured not only by the Osp Cave with the remains of the mediaeval defence wall but also the numerous finds from Roman times that emerged during farming activities on the grasslands of Grubeljce and Na vardi. The reports surrounding these early finds were scarce and only a handful of these found their way to museums, while the majority were lost. In 1880, the Osp site was inspected by the Trieste natural scientist and archaeologist Carlo Marchesetti, while the first excavations only started in 1897. They were led by Karl Moser and the finds became part of the collection of the Trieste museum. After these initial excavations at the end of the 19th century, the sites near Osp slowly slipped into oblivion, while the speleological and hydrologic research into the Osp Cave that began towards the end of the 19th century were re-started in the 1920s. The cave received numerous visits from Trieste cave explorers and amateur archaeologists, who excavated several prehistoric, Roman and medieval finds in the large entrance hall. Today, these are kept in Trieste. With a lack of other systematic archaeological research, today’s knowledge of the settlement of Osp Cave primarily relates to these finds. Osp is among the oldest villages in Slovenia. Its history goes back to Late Antiquity or the Early Middle Ages, when the broader area of the village (Hospum, Villa Hospe, Ospo) was under the Trieste diocesan county. Together with other villages, it came under the rule of the Bishops of Freising in 1067. It was made part of the Koper Commune in 1254 together with other villages from the Karst edge and it remained in this framework as an important Venetian frontier stronghold till the end of the 18th century. The vicinity of the Austro-Venetian border, Ottoman invasions that grew stronger at the end of the 15th and the beginning of the 16th centuries and the Aus-tro-Venetian wars in the 16th century called for fortified strongholds and natural sanctuaries, such as the Osp Cave. The reports of the Koper podestàs and captains from this period speak of repeated frontier battles and endeavours to maintain these fortifications and equip them with arms.The swifter economic, cultural and educational development of the village related to the political and administrative changes taking place in the 19th century and especially to Trieste’s successful and dynamic development. In 1819, the village had the first Slovene primary school in Istria, in 1897 the Domovina choral and reading society and in 1900 the Loan and Cooperative Society. The universal economic and cultural progress was mostly due to the longtime Osp priest, dean and member of the provincial assembly Josip Kompare (1858-1925). During the two world wars and the National Liberation War, Osp and the neighbouring Gabrovica were the scene of important events that were crucial for the national liberation war in the Slovenian Istria. After the war, its former importance and the economic pulse of the village strongly declined due to the broken ties with Trieste and the migration of the locals. Today’s appearance of the village draws numerous visitors from near and far. This is especially true for the upper part of the village below the rock with its mostly preserved traditional architectural heritage with high quality masonry facilities from previous centuries Pustova domačija (the Pust Homestead), the old oil mill / olive press and the activity of the Domovina Cultural and Arts Association that nourishes the traditions of social life as it was in the late 19th century, as well as reviving old customs. Since the late 1970s, the steep cliffs have been inviting numerous climbers from Slovenia and abroad. Another interesting aspect is the sub - Mediterranean ornithofauna. Specific microclimatic conditions – i.e. the characteristic southern position, bedrock and the vicinity of the sea – make Osp the only larger Mediterranean habitat in Slovenia and the wall above the village is a true peculiarity, represented by the Moehringia tommasinii blooming in April.